Electrosurgical apparatus



R. H. MAXSON ELECTROSURGICAL APPARATUS May 21, 1935.

Filed April l5, 1935 Nmv L JWJNNVIWNUWWIQIWWNM lmmblmmvdxl l l l l i Patented May 21', 1935 UNITED STATES ELECTROSURGICAL APPARATUS Rolland H. Maxson, Milton, Wis., assigner to The Burdick Corporation, Milton, Wis., a corporation of Delaware Application April 15, 1933,'seria1 No. 666,297

15 anims.

ratus; more particularly to what may be termed an electro-surgical knife for severing or cutting" tissue, etc. in connection with surgicalA operations. High frequency currents have heretofore been employed in surgery with considerable success. Such currents produced by spark gap oscillator circuits and comprising damped waves are particularly effective in producing coagulating effects upon or within tissues adjacent the active electrode. On the other hand, high frequency currents produced by vacuum or radio tube oscillator circuits and comprising undamped waves are particularly effective in severing or cutting tissue l5 at the active electrode. One of the principal difficulties or disadvantages inherent in the use of damped wave high frequency (spark gap oscillator) currents in surgery is that the severance of tissue is so slow that the necessarily prolonged application of heat results in injurious dessication or dehydration of tissue and consequent delay and other complications in healing. On the other hand, the use of undamped Wave highfrequency (vacuum tube oscillator) currents eiects such rapid cutting and so little coagulation that excessive bleeding may occur at an incision.

Hereto'fore, therefore, the use of high frequency currents in acusection has been limited to situations where relatively little cutting was requiredmaking feasible the employment of spark gap oscillator (damped wave) currentsor where relatively little bleeding was to be expectedmaking feasible the employment of vacuum tube oscillator (undamped wave) currents-or to instances Where it was possible first to apply an electrode supplying cutting (undamped wave) current and then immediately to follow with an electrode supplying coagulating (damped wave) current. The limitations of either type of high 10 frequency current Vand the danger and additional time required for sequential application of both types of current have constituted serious obstacles to the extension of electro-surgical technique, even though conditions might otherwise indicate the desirability o'f this form of therapy.

One of the objects of my invention is to provide electro-surgical equipment which combines the advantages of both undamped wave and damped wave currents for surgical technique.

Another object is to provide apparatus whereby a single active electrode may possess simultaneously both the attributes of rapid cutting and effective coagulation.

Another object is to provide equipment which will deliver to a common active electrode 'electri- (Cl. ivi- 177)V My invention relates to electro-surgical appa-- cal energy which is a resultant derived from electrical energy components of both damped and undamped wave type.

Another object is to provide apparatus whereby either cutting or coagulating or combined 5 cutting and coagulating currents may be applied to a single active electrode at the will of the operator.

Another object is to provide apparatus whereis simple, effective and reliable for accomplishing lo the intended results.

Other objects and` advantages will hereinafter appear.

In general, in accrdance with my invention,

I propose to combine or "mix currents consti- 15 tuting or made up of damped and undamped waves and thereby produce a current which is a resultant of the fundamental damped and undamped wave componentsand which possesses the property o'f effecting, apparently simultaneously, 20 both cutting and coagulating effects. I also make provision for the selective application to an active electrode of either damped or undamped wave trains (i. e. of the fundamental components) or a combination or resultant of both so as to 25 enable the operator to emphasize, at will, either a. cutting characteristic or a coagulating characteristic or to obtain both of these characteristics apparently simultaneously.

The accompanying drawing illustrates a typi- 30 cal circuit and arrangement of apparatus for carrying my invention into eiect.

Referring to the drawing, the equipment comprises?, general a suitable spark gap oscillator A for pr ducing electrical energy of damped wave 35 high frequency oscillating current type, a suitable vacuum tube oscillator B for producing electrical energy of undamped wave highfrequency oscillating current type, an impedance coupling transformer C to which both oscillators and the neces- 40 sary electrode or applicator may be connected, and a control switch D `i'orselectively bringinginto action either oscillator, alone or both oscillators simultaneously to govern the type of Vcurrent delivered to the active electrode. i5v

The spark gap-oscillator A comprises a stepup iron core transformer a vprimary winding 8 and a secondary winding 1, an inductance coil 8, a suitable spark gap 9 and a ground or neutral connection through 'acondenser I0. 50 The input of the spark gap oscillator A is supplied with electrical energyfrom the service line of ordinary alternating current (say cycle, 110

volt). The input energy is' applied to the transformer primary through a control Il and 55 conductors vI2 and |3. The secondary or high frequency high voltage side of the spark gap oscillator is connected to the impedance coupling transformer C by conductors |4 and l 5.

The vacuum tube oscillator'includes an iron core step-up' transformer 20 having a primary winding 2| and a secondary. winding 22, a vacuum tube 23 of the three electrode type and an inductance coil- 24. 'I'he grid 25 of theva'cuum a conductor 26, a resistance 21 and condenser 28 which are in parallel, and a conductor 29. 'The .oscillating or tank circuit comprises inductance the two applicators or electrodes 64 and 65, by4

coil 2 4, conductors 28 and 3|, condenser 30 and conductor 32.

Ihe plate 35 of the vacuum tube is connected to one terminal of the secondary 22 of transformer 20 through an inductance 36 and conductors 31 and 38 and to one terminal of coil 24 (and consequently to the oscillating circuit) through a condenser 39 and conductors 40- and 4|. The filament 42 of the vacuum tube is con- `nected by conductors 43 and 44 to the secondary winding 45 a relatively small low voltage transformer 46, which transformer has a primary winding 41. Themid-point of secondary 45 is connected by conductors 48 and 49 to a terminal of the secondary of transformer 20, toia point on induction coil 24 and to a point between a pair of codensers 50 and 5I which are bridged between conductors 43 and 44.

, The primary winding 2| and the primary 'winding 41 are connected to feed conductors 5 2 and 53 through an adjustable switch 54 and a variable resistance 55 respectively. The switch 54 controis the input to the vacuum oscillator.

' One .terminal of impedance coupling transformer C is connected to coil' 24 through conductor 55, a iixed condenser 56 and a variable condenser 51. The other terminalof transformer C is connected to coil 24 through a conductor 58.

The two service terminals 60 and 6| of the apparatus are connected -to impedance coupling transformer C by conductors 62 and 63 respectively. These terminals are for the connection of means of which the high frequency current is applied to the patient-the' ground electrode 54 generally consisting of a plate of considerable s lze upon which the body of the patient lies and the active electrode 65 consisting of a wire or applicator of any desired type and shape depending upon the character and location of the operation to be performed.

Thus the oscillator A is provided with an output circuit which includes coil C between conductors 62 and 63, and the conductors 62 and 63,

terminals 60 and 6|. 'I'he oscillator B is provided with an output circuit including coil 24 between the conductors 55 and 58, conductors 58 and 62, conductor 55 with the condensers 56 and 51 therein, coil C between conductors 55 and 63, and conductor 63. That output circuit of the oscillator B is also adapted to energize the service terminals 60 and 6|. In other words, the output circuits just described are connected in parallel to each other and both are connected to the service terminals 6U and 6|, which may be connected as illustrated inthe drawing to the electrodes 64 and 65, respectively, to provide an applicator circuit.

It will be seen from the foregoing that the oscillator output circuits may be referredto as parallel connected branches of a circuit including an tube is connected to one end Vof coil 24v through and which is adapted to energize the serviceapplicator branch electrically connected and common to .the parallel connected branches.

Thus, output circuits or branches being arranged to supply energy to the applicator circuit or branch may be considered as sources of energy or as oscillators, which, like the output circuits or branches, are connected in parallel.

The control switch D, which preferably may be actuated by the foot of the operator, includes a movable spark gap oscillator control contact 10, a movable vacuum tube oscillator control contact 1| and a combined oscillator control contact 13. Contacts 10, 1| and 12 are connected to one side of the service mains 13, the other side being connected to conductors. I3 and 52. A suitable line switch 14 may be interposed between the source of power and the control switch.

The impedance of the spark gap oscillator circuit should be relatively low as compared to that of the vacuum tube oscillating circuit and that of the output circuit (i.e., the circuit including the electrodes and the patients body); and the impedance of thevacuum tube oscillating circuit should be high as compared to the impedance of. the output circuit. This rrelationship will permit each oscillator to feed current properly to the output or patients` circuit without feeding, 'at

least to an objectionable degree, into the other oscillator. The amount of the current delivered to the output circuit of the spark gap oscillator may be varied to give the. desired intensity at the active electrode by adjusting the spark gap or the input control switch The amount of current delivered to the output circuit by the vacuum tube oscillator may be varied by' adjustl ing the variable condenser 51 or the input control tive electrode 65. If it is desired to apply only vacuum tube oscillator current, switch 1|A is closed, completing a circuit to the vacuum tube oscillator. Upon the closing of this switch high frequency undamped oscillations are delivered to the active electrode. In the event that it is desired to utilize simultaneously currents of both damped and undamped wave characteristics, switch 12 is closed whereupon circuits are completed from the power line to both oscillators. Upon the clbsing of this switch the current delivered to the active electrode is a resultant of the fundamental components, i. e., of the damped and undamped waves.

Having thus explained and illustrated the nature and an embodiment of my invention, what I claim and desire to secure by-United States Letters Patent is as follows:

1. An electro-surgical apparatus comprising an oscillator for producing damped current waves, an oscillator for producing .undamped current waves, an applicator circuit, and a transformer having a common terminal with each said oscillator and said applicator circuit and having a terminal for each said oscillator and for said applicator circuit at potentials different from the potential of said common terminal.

2. In'an electro-surgical apparatus including a pair of oscillators capable of producing damped and undarnped electrical oscillations, the combination of an applicator electrically associated with both oscillators for deriving energy therefrom, with' means in the output from each said oscillator electrically associated with said applicator for maintaining a predetermined ratio between the amounts of energy derived from said oscillators by said applicator, and means for selectively varying the ratio.

3. An electro-surgical apparatus comprising a damped-wave current oscillator, an applicator circuit, a coil interposed between said oscillator and said applicator circuit for inducing energy into said applicator circuit, an undamped-wave current oscillator electrically connected across the terminals of said coil, and switches whereby a source of current may be selectively connected separately to either and simultaneously to both oscillators to render either alone or both simultaneously effective upon said applicator circuit to cause said circuit to deliver either damped or undamped waves or a derivative of both types of current. v

4. An electro-surgical apparatus comprising a vacuum tube oscillator circuit, a spark gap oscillator circuit, eachsaid oscillator circuit having an output circuit, the output circuits including a common applicator branch electrically connected with respect to each said oscillator circuit in parallel with the output circuit of the other oscillator circuit and switch means whereby a source of energy may be selectively connected toI either and to both oscillator circuits to render either alone or both simultaneously effective upon said common applicator branch, said oscillator circuits including means for causing substantially all of the energy derived from each said oscillator circuit to be delivered to said applicator branch. 5. An electro-surgical apparatus comprising an electro-surgical applicator circuit, a spark gap oscillator circuit and a vacuum tube oscillator circuit, said circuits being connected in parallel and including means for causing substantially all of the energy derived from each said oscillator circuit to be supplied to said applicator circuit. y, 6. In electro-surgical apparatus having a source of high frequency cutting energy, a source of high frequency coagulating energy conjointly operable with the said source of high frequency cutting energy, a ground electrode, and an applicator electrode, means electrically connecting said sources of energy in parallel and to said electrodes,

and means associated with each said source of energy for causing substantially all of the energy from the other said source of energy to be delivered to said applicator and ground electrodes.

7. An electro-surgical apparatus comprising a vacuum tube oscillator, a spark gap oscillator, each said oscillator having an output circuit, said output circuits including a common applicator branch electrically connected with respect to each oscillator in parallel with the other oscillator.

8. An electro-surgical apparatus comprising a vacuum tube oscillator output circuit, a spark gap oscillator output circuit, each oscillator output circuit including means of low impedance for its own energy and of high impedance for the energy of the other oscillator output circuit, an applicator circuit, a coupling connecting the oscillator output circuits in parallel relation to each other and both to the applicator circuit, and means for varying the energy either oscillator output circuit may impart to the applicator circuit.

9. An electro-surgical apparatus comprising a damped-wave-current output circuit, an undamped-wave-current output circuit, each output circuit including means of low impedance for its own energy and of high impedance for the energy` of the other circuit, an applicator circuit/a, coupling connecting the output circuits in parallel relation to each other and both to the applicator circuit, and means for varying the energy either output circuit may impart to the applicator circuit.

` l0. An electro-surgical apparatus comprising a vacuum tube oscillator output circuit, a spark gap oscillator output circuit, an applicator circuit, a coupling connecting the oscillator output circuits in parallel relation to each other and both to the applicator circuit, and means associated with each oscillator output circuit for varying the energy such oscillator output circuit may impart to the applicator circuit.

11. An electro-surgical apparatus comprising a vacuum tube oscillator output circuit, a spark gap oscillator output circuit, an applicator circuit, a coupling connecting the oscillator output circuits in parallel relation to each other independently of the applicator circuit and both to the applicator circuit, and means associated with each oscillator output circuit for varying the energy such oscillator output circuit may impart to the applicator circuit.

l2. An electro-surgical apparatus comprising a vacuum tube oscillator output circuit, a spark gap oscillator output circuit, each oscillator output circuit including means for opposing the flow therethrough of energy from the other oscillator output circuit, an applicator circuit, a coupling connecting the, oscillator output circuits in parallel relation to each other and both to the applicator circuit, and means for varying the energy either oscillator output circuit may impart to the applicator.

13. An electro-surgical apparatus comprising an oscillator for producing energy of a predominantly cutting characteristic and having an output circuit, an oscillator for producing energy of a predominantly coagulating characteristic and having an output circuit, each output circuit including means of low impedance for its own energy and of high impedance for the energy of the other output circuit, an applicator circuit, a coupling connecting said oscillator output circuits in parallel relation to each other and both to the applicator circuit, and means associated with the oscillators for varying vthe energy imparted thereby to the applicator circuit.

14. An electro-surgical apparatus comprising a source of damped current waxes, a source of undamped current waves, an electro-surgical applicator, and coupling means having a common electrical terminal at ground potential with said electro-surgical applicator and each said source of current waves, said coupling means, said electro-surgical applicator, and each said source of current waves respectively having other terminals conductively related to each other and at potentials different from the potential of said common terminal.

15.111 an electro-surgical apparatus including a pair of oscillators capable of producing damped and undamped electrical oscillations, the combination of an applicator electrically associated with both oscillators, for deriving energy therefrom, with means in the output from each said oscillator electrically associated with said applicator, for maintaining a predetermined ratio between the amounts of energy derived from said oscillators by said applicator.

ROLLAND H. MAxsoN 

